I installed 3 new Dorman(CHINESE) syncro units back the 2nd week of October (2) #689-104 (1996-1997 3.0L Vulcan) and (1) #689-107 (this was for a 98 3.0L Vulcan) . I put one in my brothers 97 GL, 1 in my mother-in-laws 97GL an the other into my mothers 98 SE.
The reason I went a head and chaged these 3 is in a thread I made about my wifes GL Here>Read Here
Fast forward to last night, my brother said his car was leaking oil horribly. I checked it out and it was coming out of the sensor on top the new syncro. When I pulled the sensor off it was completly full of oil. WTF! I yanked the syncro unit out and I was totally Horrified. The roll pin in the gear was split in half and falling out of the gear and the gear was loose on the damn shaft....this is a press fit application(supposed to be). It also wore the thrust washer on top the gear. JUNKED! 2500 miles. I was fortunate it did not grenade his engine.
So I go pick up the mother-in-laws and pulled it out.....the freaking gear was loose on that one and had play in it also...not totally failed yet but was already stressing the pin horribly and it has oil weeping under the sensor already. JUNK #2. around 1500 miles.
I then go pick up my mothers 98 and you guessed it...the freaking pin and gear are loose here also...JUNK.
These units WILL FAIL! I fortunatly had all the old units lying on a shelf and put them back in till my Reman units(A1 Cardone...USA) come in Monday. The parts house was astonished but not suprised....loose tolerances and sub-standard metallargy.
Do yourself a favor if you are using one remove it and inspect it ASAP! I could understand finding a bad part out of a barrel but all three is a whole other ballgame.
BTW, Im going to pull the Reman-Napa(actually A1 Cardone) out of my wifes tommorow to see how it looks. I BET it is perfectly fine.